export function create_key(leng: number): string {
  leng = leng == undefined ? 16 : leng //如果没设置key长度自动为16位
  //预设随机字符串
  const chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz23456789'
  let key = ''
  //以长度单位进行循环
  for (let i = 0; i < leng; ++i) {
    key += chars.charAt(Math.floor(Math.random() * chars.length))
  }
  return key
}
